Method limit

include/fmt/base.h:1866–1870

  constexpr explicit fixed_buffer_traits(size_t limit) : limit_(limit) {}
  constexpr auto count() const -> size_t { return count_; }
  FMT_CONSTEXPR auto limit(size_t size) -> size_t {
    size_t n = limit_ > count_ ? limit_ - count_ : 0;
    count_ += size;
    return min_of(size, n);
  }
};

template <typename OutputIt, typename InputIt, typename = void>